Raccoon dogs at Wuhan market emerge as possible Covid origin source in new study

New data linking Sars-CoV-2 to raccoon dogs in a Wuhan wet market provides “important incremental evidence” supporting the hypothesis that the virus originated in wildlife, and not in a lab, according to reports late on Thursday.

The reports cite findings by a French researcher who chanced upon the genome sequences of samples taken from the Huanan market in Wuhan, to which several of the earliest Covid-19 patients were linked, the Atlantic reported.

The news magazine Science identified this scientist Florence Débarre, a theoretician who specialises in evolutionary biology and works at the French National Centre for Scientific Research. Débarre found data by Chinese researchers on a virology database GISAID in which samples positive for Sars-CoV-2 also had animal genetic material, mostly of raccoon dogs.

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Racoon dogs have long been seen among likely intermediate hosts for the coronavirus, given how frequently the pathogen has infected them, in the same way as bats have been.

Since Débarre spotted the sequences, GISAID had removed them, noting that this was at the request of the submitter, Science said in its report.

The findings are a strong indication that the mammals, reportedly sold live in the food market, were infected, said Dominic Dwyer, a medical virologist and infectious diseases physician, according to Bloomberg.

“It’s not the ‘eureka’ moment, but it’s a pretty big advance,” said Dwyer, who was part of the joint mission to study Covid’s origins led by the World Health Organization (WHO) in early 2021. The material was collected in an area of the market where cases were known to have occurred, he said in an interview on Friday.

“It still doesn’t tell you how did it get into a raccoon dog, or how did it get into a human, but it’s important circumstantial evidence,” said Dwyer, a clinical professor of medicine at the University of Sydney.

The new findings advance efforts to decipher the deadly contagion’s creation story, which have been frustrated by a geopolitical blame game. Some groups, including the US Department of Energy and the Federal Bureau of Investigation, support the hypothesis that Sars-CoV-2 originated in a Chinese lab. The latest data shifts the weight of evidence firmly in favour of an animal origin, Dwyer said.

Experts have said that the new findings should renew pressure on China to be more forthcoming with data, and carry on some investigations, such as into the origin of the raccoon dogs and how they landed at the animal market.

The World Health Organisation called on China to fully share genetic data that may help discern the origins of Covid-19 after it appeared briefly appeared on an international database.

The data could have and should have been shared three years ago, WHO Director-General Tedros Adhanom Ghebreyesus said Friday at a press conference.

“We need to look at the full picture,” Maria Van Kerkhove, the WHO’s top epidemiologist on Covid-19, said at a press briefing Friday. “The big issue right now is that this data exists and that it is not readily available to the international community.”

The records accessed by Débarre was initially submitted by the Chinese Center for Disease Control and Prevention and are currently being updated with newer, additional data as part of review of the manuscript that’s been submitted for publication, GISAID said in a statement to Bloomberg.

Asked for comment on the latest findings, China said only that it would continue to cooperate in global origins tracing studies.

“In the global science community, there are many clues pointing to multiple origins of the virus,” foreign ministry spokesman Wang Wenbin told reporters at a regular press briefing in Beijing on Friday. “We hope information could be shared with China on the outcomes of origins studies across the world.”